a)=-720

b)=616

c)=10000

d)=-60000

a) 12 . ( - 5 ) . ( - 2 ) . ( - 6 )

= - 60 . 12

= - 720

b) ( - 4 ) . 7 . 11 . ( - 2 )

= - 28 . ( - 22 )

= 616

c) 25 . ( - 5 ) . 4 ( - 20 )

= - 125 . ( - 80 )

= 10 000

d) 125 . ( - 3 ) . ( - 8 ) . ( - 10 )

= - 375 . 80

= - 30 000

\(a.20-\left[30-\left(5-1\right)^2\right]\)                             \(b.75-\left(3.5^2-4.2^3\right)\)

\(=20-\left[30-4^2\right]\)                                       \(=75-\left(75-4.2^3\right)\)

\(=20-14=6\)                                          \(=75-\left(75-32\right)\)

                                                                 \(=75-43=32\)

a)\(\left(-3\right).8.\left(-2\right).5=\left(-3\right).\left(-2\right).8.5\)

                                          \(=6.40=240\)

b)\(127-18.\left(5+6\right)=127-18.11\)

                                             \(=127-198=-71\)

c)\(125-\left(-75\right)+32-\left(48+32\right)=125+75+32-48-32\)

                                                                              \(\left(125+75\right)+\left(32-32\right)-48=200-48=152\)

d)\(3.\left(-4\right).2+2.\left(-5\right)-20=-12.2+2.\left(-5\right)-20\)

                                                             \(=\left(-12-5\right).2-20=-17.2-20=-140-20=-160\)

Chúc bạn học tốt

Vì  ( − 1 ) . ( − 2 ) . ( − 3 ) ... ( − 20 ) > 0 ( − 3 ) . ( − 4 ) . ( − 5 ) ... ( − 23 ) < 0 ⇒ ( − 1 ) . ( − 2 ) . ( − 3 ) ... ( − 20 ) > ( − 3 ) . ( − 4 ) . ( − 5 ) ... ( − 23 )

6561 a⁵ - 95 547 843

kết quả là -1/3

1) 5 + (-4) = 1

2) (-8) + 2 = -6

3) 8 + (-2) = 6

4) 11 + (-3) = 8

5) (-11) + 2 = -9

6) (-7) + 3 = -4

7) (-5) + 5 = 0

8) 11 + (-12) = -1

9) (-18) + 20 = 2

10) (15) + (-12) = 3

11) (-17) + 17 = 0

12) 16 + (-2) = 14

13) (30) + (-14) = 16

14) (-19) + 20 = 1

15) (-18) + 15 = -3

16) (10) + (-6) = 4

17) (-28) + 14 = -14

18) 15 + (-30) = -15

19) (15) + (-4) = 11

20) (-21) + 11 = -10

21) 8 + (-22) = -14

22) (-15) + 4 = -11

23) (-3) + 2 = -1

24) 17 + (-14) = 3

25) 17 + (-14) = 3

thế này đọc đc mới đỉnh

a ) 5 ^30 : ( 5^25 . 6 + 5^25 . 9 ) 

 = 5^30 : [ 5^25 ( 6 + 9 ) ]

 = 5^30 : [ 5^25 . 15 ]

 = 5^30 : [ 5^25 . 5 . 3 ]

 = 5^30 : [ 5^26 . 3 ]

 = 5^30 : 5^26 : 3

  = 5^4 : 3

b ) ( 20 . 2^4 + 12 . 2^4 - 48 . 2^2 ) : 8^2

   = ( 20 . 2^4 + 12.2^4 - 12 . 2^2 . 2^2 ) : 8^2

   = ( 20 . 2^4 + 12.2^4 - 12.2^4 ) : 8^2

   = 20 . 2^4 : 8^2

   = 5 . 2^2 . 2^4 : ( 2^3 )^2

   = 5 . 2^6 : 2^6

   = 5

  = 625 : 3

  = 625/3

Lần sau viết đề dễ nhìn chút nhé!Nhìn là thấy không muốn làm rồi.

a) \(5^{30}:\left(5^{25}.6+5^{25}.9\right)\Leftrightarrow5^{30}:\left[5^{25}.\left\{6+9\right\}\right]\)

\(\Leftrightarrow5^{30}:\left[5^{25}.15\right]\)

Bỏ ngoặc đi ta lại có: \(5^{30}:5^{25}.15\)

Theo quy tắt khi phép tính không có ngoặc thì ta làm từ trái sang phải. Ta có:

\(\left(5^{30}:5^{25}\right).15\Leftrightarrow5^{30-25}.15\Leftrightarrow5^5.15\)

\(\Leftrightarrow3125.15=46875\)

b) \(\left(20.2^4+12.2^4-48.2^2\right):8^2\)

\(\Leftrightarrow\left\{\left[2^4.\left(20+12\right)-48.2^2\right]:8^2\right\}\)

\(\Leftrightarrow\left\{\left[2^4.32-48.2^2\right]:8^2\right\}\)

\(\Leftrightarrow\left\{\left[16.32-48.4\right]:64\right\}\)

\(\Leftrightarrow\left\{\left[512-192\right]:64\right\}\Leftrightarrow320:64=5\)

\(\frac{4^5.9^5-2.6^{10}}{2^{10}.3^9+6^9.20}=\frac{\left(4.9\right)^5-2.2^{10.}.3^{10}}{2^{10}.3^9+2^9.3^9.2^2.5}\)

\(\frac{2^{10}.3^{10}^{ }-2^{11}.3^{10}}{2^{10}.3^9+2^{11}.3^9.5}=\frac{2^{10}.3^{10}\left(1-2\right)}{2^{10}.3^9\left(1+2.5\right)}\)

\(\frac{2^{10}.3^{10}.\left(-1\right)}{2^{10}.3^9.\left(-9\right)}=\frac{-3}{-9}=\frac{1}{3}\)